Casing spear



Patented May 5, 1925.

UNITED STATES BERT R. RMRICK, or NYAUNGHLA, UPPER BURMA, INDIA. y

casING sPEAR.

Application led June 14, 192.2. Serial Nfo. 5,648,184.

, To all 'whom t may concern:

Be it known that I, BERT R. EMRTCK, a citizen of the United States, residing at Nyaunghla, UpperfBurma, india, have invented certain new and useful lmprovements in Casing Spears, of which the following is a specification.

This invention is for a Vcasing spear of the kind used for withdrawing casings in well drilling` operations.

A large number of different forms of casing spears are' in use, but many of them frequently do not catch at the proper time, and are more or less ofsuoh delicate con` struction that the tripping mechanism is unreliable, with the result that vthe operator takes a great chance of`not being able to free his spear in the event that it becomes necessary.

The present invention has Vfor its primary objects the provision of a st-rong casing spear of relatively simple construction, which will be positive in its operation to either pipe gripping` or pipe releasing posi tion.` g

Other objects are to provide a spear which is more or less self-cleaning and which may be adapted for use in connection with rotary systemsof drilling.

My invent-ion may be readily understood b reference tothe accom an in drawings y t. e

in which:

V:Fig 1 is a side elevation of the casing spear, with the parts in open position;

. Fig, 2 is a similar view showing the parts moved to gripping position;

Fig. 3 is a vertical section through Fig. 1;

Figs. 4, 5, 6 and 7 are transverse sections on the planes of lines IVMIV, V-V, VI- Vl. and VII-VH, respectively;

Fig. 8 is a view corresponding to Fig. 3, showing a slightly modified construction for use in rotary drillingoperations.

ln the drawings, A indicates the body of the spear, which body has a reduced, tapered, threaded end 5 of usual construction, and a squared portion 6` to which a wrench may be applied. At 7 the diameter of the body increases, providing a shoulder. Below the shoulder are a plurality of, preferably three, substantially flat faces 8' which are inclined away from the longitudinal axis of the body toward the lower or bottom end thereof. These faces are separated one from the other by peripheral portions'9 of the body. Designated as 10 are segmentshaped shoulders which are formed above theflat inclined faces. ln each of the faces 8 isa dovetail slot 8a.

The body of the spear below the faces 8 is materially reduced at 11, it` extending downwardly from point 11 to the end of Y the spear as a cylindrical mandrel 12.4 The lower end of the mandrel is threaded at 13. Surrounding the upper portion of the mandrel, and slidable thereon, is a collar 15 having an annular groove 16 Vin its periphery. Y Y A Slidably mounted on each face 8 of the body, is a casing-engaging and pulling wedge or slip 17. These wedges, which are toothed transversely in order to enter into lifting engagement with af pipe or casing, haveV roundedvfaces to conform with the curvature of the spear and taper in width from the top 'downwardly to correspond to the decrease downwardly in the width of the faces SQ The wedges increase in thickness from the bottom towardV the tops thereof, the slope of the inner faces ofthe wedges corresponding to the slope downwardly of faces 8. Consequently, thewwedges move radially outwardly when they move upwardly thereof. Each wedge 17 has a dove-tail rib 17a on its inner face to engage in groove 8 of the face 8 on which the slip engages.

The upward movement of the slips is limited by shoulder 10. The lower end of each slip is provided with an inwardly turned transversely extending lug17j. These lugs are ventered into groove 16 of collar 15. Thus, the slipsmay all move in unison with collar 15.

In the parts 9 of the body 'are reciprocable pins 18 slidably retained in position by screws 19, and vielaably urgeddownwardly by springs 20. The outer ends of these pins engage the collar 15 to urge the collar away from the shoulder at 11.

Slidable on the mandrel 12, belowcollar 15, is a second collar 21 which may be termed the bottom slip block, This block is provided with a plurality of, four being shown, longitudinally extending dove-tail grooves 22. These grooves increase in depth from the top toward the bottom, and loosely slidable in each groove is a lower slip 23. Slips 23 are smaller than slips 17, and are of suitable shape to be received in the dove-tail grooves 22. They increase in thickness from their Vtops toward their bottoms to correspond to the slope of the dove-tail grooves,

so that fwhen their tops are at the upper limits of grooves A22, their peripheries protrude beyond the periphery of the lower slip block, as shown Vin F ig. 2. rIhe peripheries of the lower slips are provided with transverse teeth which are reversed to the teeth on slips 17, so that they bite ,the pipe when the spear is urged downwardly, as hereinafter described. A

Screwed onto the lower threaded end of mandrel 12 is a normally listed collar 25, and a pin 26 may be employedbelow this collar toprevent accidental loss thereof. I

In the mandrel 12, a short distance above its Alower end, is a transverse slot 27. In this slot, and -pivoted on pin 28, are two dogs 29 having shoulders v29a at their upper ends. The upper ends of the two pivoted dogs are urged outwardly by a spring 30.

In eperation, the parts are normally in the position shown in Fig. 1. Collar 15 is spaced slightly away from the shoulder at 11so that upper slips 17 yare almost, but not q'uite,.in ltheir uppermost positions, being moved to this position by spring pushed pins 18. In this position, they are in a contactnon-biting engagement witha pipe when the 'spear islinserted. Lower slip carrying block 21,'is elevated above end collar 25, but is not Aquite in its uppermost position. Locking dogs l2,9 are accordingly held against outward movement. The lower slip block is held in this posit-ion by a thin stick of wood a; shownfin F ig. 1', which stick is disposed between 'the block'and end collar 2'5. Bottom slipsf21'slide down, by gravity, to the position shown in Fig. 1, collar 25 preventing them from coming out.

The "spear, which has previously been attaehed to vthe drill string or cable, is lowered in't'o the casing. IVhen it is desired to seit thec'asin-g, a sudden upward jerk is applied to the cable, displacing or breaking stick Lower slip block 21 moves downwardly, by gravity, 'forcing bottom slips 23 outwardly. Collar 15 also moves down.l together with upper slips 17. As slips 17 move down, they ride out into pipe-engaging position.

Upon the ycable then heilig pulled tight, upper slips 17 `catch the casing for withdrawing it. As the strain on the cable increases, slips 17 are urged further downwardly and outwardly. Should it become necessary to release the spear, pressure is applied 'downwardly on the body A..

Lower'slips 23, which are in pipe-engaging position, resist downward movement, whereupon the mandrel 12 slides inside the lower slip block 21. As collar 15 rests against thetop of block 21, the body also moves downward relatively to collar 15 and upper slips, 17 lVhen thev body has moved sullicientlyffar 'downward for slips 17 to be in retractedposi'tion and collar 15 is against the shoulder 11, the lower end of block 21 will be above the shoulders 29a enabling the dogs to spread. As soon as the dogs have spread, the .parts will be locked, with the upper lifting slips 17 in retracted position. Upon pulling up on the cable to withdraw the spear, slips will move downwardly out of pipe-engaging position.

It will thus be seen that, while comparatively simple in construction, and without the employment of delicate mechanisms, and by the provision of two sets of slips, a positively acting spear is provided.

In order to provide for the escape of dirt, channels or 'grooves 32 may be provided in shoulder@ 7, through which dirt may be forced when slips 17 move upwardly. y

It sometimes happens in rotary drilling operations, that the drill vstem will part, and the part of the stem in the hole will have to be withdrawn by using a casing spear.` Inasinuch as water and mud passes down 'the drill stemv and up 4the hole, there will be a sediment which will collect around the lower end of the pipe and prevent it being withdrawn.

The inodii'cation shown in Fig. 8 is a construction adapted for withdrawing a rotary drill 'stem under such conditions.v The construction is substantially identical with that hereinbefore described, with the exception of the locking dogs, and the same reference numerals have been employed, except as to this part of the structure.

The body A has a longitudinal bore a passingtherethrough from one end to the other. Instead of a transverse slot 27 being formed in the lower part of the mandrel, recesses 27 are formed. In each recess is a pivoted dog 29, similar to dogs 29 hereinbefore described. Each dog 29 is urged outwardly by a lealil spring 30. Thus, the passage through the body is continuous.l and water passed -therethrough may not escape untilr it reaches the lower end of the spear.

In use, the spear is carried at the lower end of a lstring of pipe. It is lowered into the well and entered into Vthe broken drill stem, and set. After it is set, a large quantity of water may be passed down the string of pipe and through the spear, into the lower part or' the drill stem. Some of the water will, of course, escape around the spear, but much of it will flow down to the bit at the lower end of the stem, and loosen the sediment around the lower end of' the drill stem.

Various changes and modilications may be made in the construction of the tool within the contemplation Vof my invention, and within the scope of 'the appended claims.

I claim:

1. A casing` spear comprising a i'nandrel having slipsslidable ontheupper partthereot,'-a wedge member slidable on the mandrel lllll below the slips, lower slips in contact with the wedge member, said mandrel being recessed below the top of said wedge member, pivoted dogs in the recess having means thereon for engaging the wedge member `when it is in itsuppermost position to prevent downward movement thereof, and resilient means for urging the dogs into wedge engaging position, said dogs normally being confined by thel wedge member when said wedge member is below the uppermost limit 'of movement,the topof said wedge member transmitting motion to said upper slips.

2. A casing spear comprising a mandrel having slips slidable ojn'the upper part thereof, a wedge member slidable on the mandrel below the slips, a ring slidable on the mandrel interposed between the wedge member and the upper slips, the upper slips being connected with' said ring, lower slips in contact with the wedge member,1said mandrel being recessed below the top of said wedge member, pivoted'dogs in the recess having means thereon for engaging the wedge member when it is in its uppermost position to prevent downward movement thereof, and resilient means for urging the dogs into wedge engaging position, said dogs normally being confined by the wedge member when said wedge member is below the uppermost limit of movement, the top of said wedge p member transmitting motion to said upper slips through said ring.

3. A casing spear comprising a mandrel having slips slidable on the upper part thereof, a wedge member slidable on the mandrel below the slips, lower slips in contact with the wedge member, said mandrel being recessed below the toprof said wedge member, pivoted dogs in the recess having means thereon for engaging the wedge member when it is in its` uppermost position to prevent downwardmovement thereof, resilient means for urging theV dogs into wedge engaging position, said dogs normally being confined by" the wedge member when said wedge member is below the uppermost limit of movement, the top of said wedge member transmitting motion Ato said upper slips, and means for resiliently urging the wedge member below the uppermost limit of its move ment.

4. A casing spear comprising av mandrel having slips slidable on the upper part thereof` a wedge member slidable on the mandrel below the slips, a ring slidable on the mandrel interposed between the wedge member and the upper slips, the Vupper slips being connected with said ring,lower slips in contact with the wedge member, said mandrel being recessed below the top of said wedge member, pivoted dogs in the recess having means thereon for engaging the wedge member when lit is in its uppermost position to prevent downward movement thereof, re-

thereof, a slidable wedge member on theV mandrel below the slips, said mandrel having a pocket formed therein near its lower end, adog pivoted in the pocket.y a spring for urging the dog outward, said dog nor` mailt7 being conned by said slidable wedge member, lower slips engaging the slidable wedge member, said dog` being adapted to project into position under the wedge member to hold said wedge memberagainst loweringmovement when it has been forced to its uppermost limit. l

6, A casing spear comprising a mandrel having upper slips slidable on the upper part thereof, a slidable wedge member on the mandrel belowthe slips, said mandrel havine` a pocket formed therein near its lower end, a dog pivoted in the pockety a spring for urging the dog outward, said dog normally being confined by said slidable wedge member, lower slips'engaging the slidable wedge member, said dogbeingadapted to project into position under the wedge mem#V ber to hold said wedge member against lowring, and resilient'means en# eringmovement when it hasbeen forced to Y its uppermost limit, a ring slidable on the mandrel interposed between the bottoms of he upper slips and the top of the wedge member, said upper slips and ring having an interlocking engagement, and a spring pressed vertically movable plunger in the mandrel engaging the ringv for urging it downward to hold said wedge member above its uppermost limit of movement.

.7. A casing spear comprising a mandrel having upperslips slidable on the upper part thereof, a slidable wedge memberl on the mandrel below the slips, said mandrel having a pocket formed therein near its lower end, a dog pivoted in the pocket, a spring for urging the dog outward, said d'ognormallv being confined by said slidable wedge member, lower slips engaging the slidable wedge member, said dog. being adapted to project into positionunder the wedge member to hold said wedge member against lowering movement when it has been forced to its uppermost limit, a ring slidable on the mandrel interposed between the bottoms of the upper slips and the top of the wedge member, said upper slips and ring having an interlocking engagement, a spring pressed vertically movable plunger in the mandrel engaging the ring for urging it downward to hold said wedge member above its uppermost limit of movemen-t, and temporary holding means for releasably holding the wedge against downward movement when it is below the uppermost limit of its movement.

8. A casing spear comprising a mandrel having upper slips slidable on the upper part thereof, a slidable wedge member on the mandrel below the slips, said mandrel having a pocket formed therein near its lower end, a dog' pivoted in the pocket, a spring for urging the dog outward, said dog normally being confined by said slidable wedge member, lower slips engaging the slidable wedge member, said dog being adapted to project into position und-er the wedge member to hold said wedge member against lowering movement when it has been forced to its uppermost limit, a longitudinal passageway in the body, said recess being at one side of the passageway and `out of communication therewith.

9. A casing spear comprising a body having upper and lower sets of slips movable vertically and laterally into and out of operative position, meansslidable on the body connecting all the slips of the upper set, whereby they must move in unison, and vertically movable means on said body controlling the Iactuation of both pairs `of slips.

10. A casing spear comprising-a body hav.- ing upper and lower sets of pipe `engaging slips movable into and out of pipe-engaging position, a vertically movable block on said body controlling the actu-ation of said slips, and pivotedV dogs in said body arranged to hold said block at its uppermost limit of move-ment when said block has been moved to such position.

lfl. A casing spear comprising a body having a set of vertically `and laterally movable casing elevating slips thereon, said slips being retracted when in their uppermost position and expanded rin when .their lowermost position, and yieldable means for normally urging -said slips :downwardly away from theiruupperm-ost posi-tion into a partially expanded position, in which lposition they are adapted to contact with #but not 'grip :the walls vof a casing when inserted therein.

'12. Acasing spear comprising-a body having Ava set of vertically :and laterally 'movable casing elevating slips thereon, :said slips being fully retracted in vtheir uppermost position and vfully expanded -in their lowermost position, means slidable on the body with which the slips are connected whereby they may move in unison, and yieldable means 2 grooves in said shoulder through which foreign matter may be forced upon upward movement kof the slips.

14. A casing spear comprising a. body hav- 'ing a reduced upper end, a middle portion of larger diameter, and a lower mandrel portion extending downwardly from the middle portion, slip-engaging faces on said middle portio-ninclined away from the longitudinal axis of the body downwardly, upper slips movable vertically over 4said faces, a ring slidable on the mandrel connecting the slips, a lower slip-carrying block slidable vertically on lthe mandrel below said ring, vertically and laterally movable lower slips thereon, an abutment on the mandrel confining the downward movement of the lower slips and block, and locking means in Said mandrel adapted to ybe projected under said block to prevent its downward movement when the block has been moved a predetermined distance above the abutment.

15. A casing spear comprising a body having a reduced upper end, a middle portion of larger diameter, and a lower mandrel portion extending downwardly from the middle portion, slip-engaging faces on said middle portion inclined away from the longitudinal axis of the body downwardly, upper slips movable vertically over said faces, a ring .slidable on the mandrel connecting the slips, a lower slip-carrying block .slidable vertically on the mandrel below said ring andabutting against said ring, whereby said ring and block may move vertically in unison, vertically and laterally movable lower slips thereon, Ian abutment on the mandrel confining the downward movement of the lower slips and block, and locking meansin said mandrel adapted to be projected under said block to prevent its downward movement when the block has been moveda predetermined distance above the abutment.

In testimony whereof I affix my signature.

BERT R. EMRIOK. 

